This invention relates to gear shift controls used in motor vehicle transmissions.
Typical motor vehicle transmissions include a plurality of longitudinally extending shifter rails upon which shifter forks are slidably mounted. Gears are individually associated with each fork and move therewith.
A shift lever extends downwardly from the cover of the transmission and terminates at a point slightly above the shifter rails so as to allow the lower end of the shift lever to selectively engage one of the shifter forks, as by capture of the lower end of the shift lever between the exposed sides of an offset arm extending upwardly from each of the shifter forks. Each of the shifter forks may be selectively positioned at a predetermined point along its associated shifter rail so as to place its associated gear in a desired relation to other gears. Movement of the shift lever is controlled by the operator of the vehicle.
When repositioning one of the shifter forks, it is desirable to prevent movement of the other forks, as only one gear should be engaged at one time. A gate is typically provided to prevent unwanted movement. Such a gate may typically comprise a flat plate mounted on gate rails for transverse movement in a plane above and parallel to the plane of the shifter rails. The gate rails extend in a direction perpendicular to that of the shifter rails. The shift lever extends through a slot in the gate and effects movement of the gate when moved in the direction perpendicular to the direction of the shifter rails. Movement of the lever in a direction parallel to the shifter rails does not cause movement of the gate.
The gate is provided with downwardly extending tabs to engage at least one shifter fork to prevent movement thereof when the shift lever engages another fork which is to be repositioned. The shift lever and gate may be returned to a neutral position when the gears are disengaged. Springs are typically provided to urge the shift lever and gate to a neutral position.
A problem associated with the above-described gear shifter is the incorporation of multiple components in the combination shift lever/selector gate, resulting in a higher cost and a less compact arrangement than is desirable. Additionally, movement of the shift lever in association with the slotted gate is a source of wear on the components.